+_public_ int sd_journal_open_container(sd_journal **ret, const char *machine, int flags) {
+ _cleanup_free_ char *root = NULL, *class = NULL;
+ sd_journal *j;
+ char *p;
+ int r;
+
+ assert_return(machine, -EINVAL);
+ assert_return(ret, -EINVAL);
+ assert_return((flags & ~(SD_JOURNAL_LOCAL_ONLY|SD_JOURNAL_SYSTEM)) == 0, -EINVAL);
+ assert_return(filename_is_safe(machine), -EINVAL);
+
+ p = strappenda("/run/systemd/machines/", machine);
+ r = parse_env_file(p, NEWLINE, "ROOT", &root, "CLASS", &class, NULL);
+ if (r == -ENOENT)
+ return -EHOSTDOWN;
+ if (r < 0)
+ return r;
+ if (!root)
+ return -ENODATA;
+
+ if (!streq_ptr(class, "container"))
+ return -EIO;
+
+ j = journal_new(flags, NULL);
+ if (!j)
+ return -ENOMEM;
+
+ j->prefix = root;
+ root = NULL;
+
+ r = add_search_paths(j);
+ if (r < 0)
+ goto fail;
+
+ *ret = j;
+ return 0;
+
+fail:
+ sd_journal_close(j);
+ return r;
+}
+